How should I start combined oral contraceptive therapy in a premenopausal woman with no contraindications?

Combined Oral Contraceptive Initiation in Premenopausal Women

Combined oral contraceptives can be started at any time if it is reasonably certain the woman is not pregnant, with no need to wait for menses, and backup contraception is required for 7 days unless started within the first 5 days of menstrual bleeding. 1

Quick Start Method: The Preferred Approach

The "Quick Start" method—initiating COCs on the same day as the office visit—is safe and effective, eliminating delays that put women at risk for unintended pregnancy. 1 This approach has been validated by systematic reviews showing no difference in pregnancy rates regardless of cycle day initiation. 2

Timing Algorithm

• Start immediately if reasonably certain the woman is not pregnant (no need for pelvic examination) 1
• If started within 5 days of menstrual bleeding onset: No backup contraception needed 1
• If started >5 days since menstrual bleeding began: Use backup contraception (abstinence or condoms) for 7 consecutive days 1

Pregnancy Exclusion Criteria

Before initiating COCs, confirm the woman is not pregnant using these criteria 1:

• No intercourse since last normal menses
• Correctly using reliable contraception
• Within 7 days after normal menses
• Within 4 weeks postpartum (non-breastfeeding)
• Within 7 days post-abortion
• Fully breastfeeding, amenorrheic, and <6 months postpartum

If uncertain about pregnancy status, start COCs anyway—the benefits exceed risks—and perform a follow-up pregnancy test in 2-4 weeks. 1

Special Populations

Postpartum Women (Not Breastfeeding)

• Absolute contraindication: First 21 days postpartum due to venous thromboembolism risk (U.S. MEC Category 4) 1, 3
• Can start at 3 weeks in women without additional VTE risk factors (U.S. MEC Category 2) 3
• Women with VTE risk factors (age ≥35, BMI ≥30, prior VTE): Generally should not use until after 6 weeks (U.S. MEC Category 3) 1, 3
• Backup contraception: Required for 7 days if started ≥21 days postpartum when menses has not returned 1

Postpartum Women (Breastfeeding)

• Absolute contraindication: First 3 weeks (U.S. MEC Category 4) 3
• Generally should not use: Weeks 3-4 postpartum due to effects on lactation (U.S. MEC Category 3) 1, 3
• Preferred timing: After 6 weeks postpartum when VTE risk normalizes and lactation is established 3
• Better alternatives: Progestin-only methods (pills, implants, IUDs) can be started immediately postpartum without affecting breastfeeding 3

Post-Abortion

• Can start within 7 days after first or second trimester abortion, including immediately post-procedure (U.S. MEC Category 1) 1
• Backup contraception: Required for 7 days unless started at time of surgical abortion 1

Switching from Another Method

• Start immediately if reasonably certain not pregnant—no need to wait for menses 1
• Backup contraception: Required for 7 days if >5 days since menstrual bleeding started 1
• When switching from IUD: Consider retaining IUD for 7 days after starting COCs, using barrier methods for 7 days before IUD removal, or using emergency contraception at IUD removal if intercourse occurred >5 days after menses 1

Formulation Selection

Prescribe low-dose COCs (≤35 μg ethinyl estradiol) with levonorgestrel or norethisterone as first-line options—they are effective, have lower VTE risk, and are cost-effective. 4 The evidence shows no clinically meaningful difference between third/fourth-generation and first/second-generation progestins for dysmenorrhea relief. 5

Evidence Supporting Quick Start

Research demonstrates that follicular activity increases with later cycle initiation, but no ovulations occurred when COCs were started at follicle diameter ≤10 mm (approximately cycle day 7.6). 1, 2 This supports the safety of Quick Start with 7 days of backup contraception. 2

Common Pitfalls to Avoid

• Don't delay until next menses: This outdated practice increases unintended pregnancy risk 1, 2
• Don't require pelvic examination: Not needed before COC initiation 1
• Don't wait until 6-week postpartum visit: Non-breastfeeding women without VTE risk factors can safely start at 3 weeks 3
• Don't forget STI screening: While not required before starting COCs, screen all sexually active patients 1

Contraindications (U.S. MEC Category 4)

COCs should not be prescribed for 1:

• Severe uncontrolled hypertension (≥160/100 mmHg)
• Migraines with aura or focal neurologic symptoms
• Current or history of venous thromboembolism
• Known thrombophilia (Factor V Leiden, antiphospholipid syndrome, protein C/S deficiency)
• Complicated valvular heart disease
• Complicated diabetes (nephropathy, retinopathy, neuropathy)
• Active liver disease
• Smokers ≥35 years old with ≥15 cigarettes/day
• First 21 days postpartum

Expected Side Effects and Counseling

Counsel patients that irregular bleeding, headache, and nausea are common initially but typically resolve after 3-6 months. 1, 5 COCs probably increase risk of any adverse events (RR 1.31) and irregular bleeding (RR 2.63) compared to placebo. 5 However, weight gain and mood changes have not been reliably linked to COC use. 1

Emphasize that 7 consecutive hormone pills are required to prevent ovulation, and provide clear instructions for missed pills. 1